So, I should be getting a 1994 K5 blazer during the summer and I want to make sure I get a good overall sound system in there.

I'm thinking probably Powerbass 4xl's in the front doors, either L3H or ST350 tweeters in the dash then a set of decent 6x9 Coax's (Suggestions welcome) in the rear roof panel (Not sure what its called?). Probably one SDC2.515 in the rear tuned to about ~38hz. The highs will be run off a PG Ryval v754 (75x4@4 ohms, 130x4@2 ohms) then the SDC will be off my AP15001D (950@2 ohms).

Anyone got any suggestions to make this setup better? My budget is whatever all that adds up to. ($250 give or take on the speakers?) I won't be buying amps, as I already own both of those, so any suggestions need to keep that in mind.